Sandwich panel connection structure

Abstract

To provide a connection structure for sandwich panels which excels in fire resistance performance.SOLUTION: A connection structure 100 for sandwich panels of the present invention is a sandwich panel connection structure where sandwich panels 1, which include: a core material 5 that has at least two principal planes 5C, 5D facing each other in a thickness direction and two side faces 5A, 5B connecting the two principal planes 5C, 5D facing each other and includes an organic core material; and a face panel 10 covering at least the principal planes 5C, 5D of the core material 5, are arranged adjacently to one another. Side faces 1X, 1Y of a pair of adjacent sandwich panels 1 are connected by an abutted connection 2, and a thermally-expansible fire-resistive material 20 is partially provided in the connection in a thickness direction of the sandwich panels 1.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a sandwich panel connection structure to be installed in a partition section of a building. [Background technology]

[0002] Sandwich panels are sometimes installed in partitions in buildings to improve fire resistance. For example, one proposed sandwich panel includes a core material made of a fibrous mat formed by compression molding rock wool fibers, and metal plates bonded and integrated to both sides of the fibrous mat (see, for example, Patent Document 1).

[0003] In conventional sandwich panels made from rock wool fiber, the insulating properties of the rock wool fiber are low, so in places where insulating properties are required, it is necessary to ensure insulating properties by adding urethane foam, which has excellent insulating properties, after the sandwich panel is installed.In addition, sandwich panels made from rock wool fiber are difficult to handle during construction because the rock wool fiber is heavy. Therefore, the use of urethane foam or the like as a core material for sandwich panels has been considered in order to improve heat insulating performance and ease of handling (see, for example, Patent Document 2). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 6-123141 [Patent Document 2] Patent Publication No. 2021-088923 Summary of the Invention [Problem to be solved by the invention]

[0005] Partitions in buildings are sometimes constructed by joining multiple sandwich panels together at their ends. Insufficient joining of sandwich panels at their ends can lead to poor flammability due to oxygen inflow, or to gaps caused by carbonization and shrinkage of the organic material, such as urethane foam, used as the core material, which can create thermal paths and reduce fire resistance. Therefore, it has been difficult to improve fire resistance while maintaining good thermal insulation.

[0006] Therefore, an object of the present invention is to provide a sandwich panel connection structure that can improve fire resistance while maintaining good thermal insulation properties. [Means for solving the problem]

[0007] The present invention has been made to solve the above problems, and the gist of the present invention is as follows. [1] A sandwich panel connection structure in which adjacent sandwich panels are arranged, each having at least two main surfaces opposing each other in the thickness direction and two side surfaces connecting the two opposing main surfaces, and each having a core material containing an organic core material and a surface material covering at least the main surface of the core material, wherein the side surfaces of a pair of adjacent sandwich panels are connected by a connecting portion where they are butted together, and a heat-expandable fire-resistant material is partially arranged in the connecting portion in the thickness direction of the sandwich panels. [2] The sandwich panel connection structure described in [1], wherein the heat-expandable fire-resistant material is arranged on at least one of the portion of the surface material covering the side surface of the core material and the side surface of the core material. [3] The sandwich panel connection structure according to [1] or [2], wherein the organic core material is an organic foam. [4] A sandwich panel connection structure described in any one of [1] to [3], in which at least one pair of the heat-expandable fire-resistant materials is provided, and the pair of heat-expandable fire-resistant materials are arranged on either side of the central portion in the thickness direction of the sandwich panel. [5] The sandwich panel connection structure according to any one of [1] to [3], wherein the heat-expandable fire-resistant material is provided at the center in the thickness direction of the sandwich panel. [6] A sandwich panel connection structure described in any one of [1] to [5], wherein the side surfaces of the sandwich panels that make up the connection portion are all provided with irregularities and are fitted together. [7] The sandwich panel connection structure according to any one of [1] to [6], further comprising a partition material at the connection portion. [8] The sandwich panel connection structure according to any one of [1] to [7], further comprising a filler in the connection portion. [Effects of the Invention]

[0008] According to the present invention, a sandwich panel connection structure having excellent fire resistance can be provided. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a schematic diagram of a sandwich panel connection structure according to an embodiment of the present invention. FIG. [Figure 2] 1 is a schematic cross-sectional view showing a connecting portion of a sandwich panel connecting structure according to a first embodiment of the present invention. [Figure 3] FIG. 4 is a schematic cross-sectional view showing a connecting portion of a sandwich panel connecting structure according to a modified example of the first embodiment of the present invention. [Figure 4] FIG. 6 is a schematic cross-sectional view showing a connecting portion of a sandwich panel connecting structure according to a second embodiment of the present invention. [Figure 5] FIG. 10 is a schematic cross-sectional view showing a connecting portion of a sandwich panel connecting structure according to a third embodiment of the present invention. [Figure 6] FIG. 10 is a schematic cross-sectional view showing a connecting portion of a sandwich panel connecting structure according to a modified example of the third embodiment of the present invention. [Figure 7] FIG. 10 is a schematic cross-sectional view showing a connecting portion of a sandwich panel connecting structure according to a fourth embodiment of the present invention. [Figure 8]FIG. 10 is a schematic cross-sectional view showing a connecting portion of a sandwich panel connecting structure according to a modified example of the fourth embodiment of the present invention. [Figure 9] FIG. 10 is a schematic cross-sectional view (part 1) showing a connecting portion of a sandwich panel connecting structure according to another embodiment of the present invention. [Figure 10] FIG. 10 is a schematic cross-sectional view (part 2) showing a connecting portion of a sandwich panel connecting structure according to another embodiment of the present invention. [Figure 11] FIG. 10 is a schematic cross-sectional view (part 3) showing a connecting portion of a sandwich panel connecting structure according to another embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0010] The present invention will be described in more detail below using embodiments.

[0011] [First embodiment] As shown in FIG. 1(a), the sandwich panel connection structure 100 according to the first embodiment of the present invention is configured by connecting a pair of adjacent sandwich panels 1 (adjacent in the X-axis direction in FIG. 1) by butting their side surfaces 1X, 1Y together at a connecting portion 2, and serves as a partition between compartments (compartments in the Z-axis direction in FIG. 1). Examples of partitions in buildings in which the sandwich panel connection structure 100 is installed include walls, partitions, floors, ceilings, and roofs, preferably walls and partitions, and more preferably exterior walls and partitions. The sandwich panels 1 in the sandwich panel connection structure 100 are assembled by having their upper and lower (Y-axis) ends held by an upper frame member 3 attached to the ceiling 3A and a lower frame member 4 attached to the floor 4A. As shown in Figure 1(b), the sandwich panel connection structure 100 of the first embodiment of the present invention has a heat-expandable fire-resistant material 20 partially arranged at the connection portion 2 where the sides 1X and 1Y of the sandwich panel 1, which has a core material 5 and a surface material 10 covering the surface of the core material 5, are butted together.

[0012] As shown in Figure 2(a), the sandwich panel 1 comprises an organic core material 5 having two opposing main surfaces 5C, 5D in the Z-axis direction (thickness direction of the panel) and two side surfaces 5A, 5B connecting the two opposing main surfaces 5C, 5D, and a surface material 10 covering the main surfaces 5C, 5D and side surfaces 5A, 5B of the organic core material 5. In the following description, the surface material 10 will be described as main surface covering portions 1C and 1D covering the main surfaces 5C and 5D of the organic core material 5, respectively, and as side surface covering portions 1A and 1B covering the side surfaces 5A and 5B, respectively. In addition to the two side surfaces (ends in the X-axis direction in FIG. 1) that make up the connecting portion 2, the sandwich panel 1 also has two upper and lower end portions (ends in the Y-axis direction in FIG. 1) that connect the two main surfaces (the XY plane in FIG. 1), which may or may not be covered with the surface material 10. The two upper and lower end portions are housed inside the upper frame material 3 and the lower frame material 4, and even if they are not covered with the surface material 10, the organic core material 5 can be prevented from burning through the two upper and lower end portions.

[0013] On the sides 1X and 1Y of the sandwich panel 1, the surface material 10 only needs to cover a portion of the side of each of the core materials 5 and 5, covering both ends in the thickness direction (Z-axis direction) of the panel and leaving the area between the ends uncovered to expose the core material 5. At each end of each panel 1, 1 in the thickness direction, convex portions 11a, 11b are provided on the side covering portion 1A of the surface material 10, and concave portions 14a, 14b are provided on the side covering portion 1B. As shown in FIG. 2(b), the unevenness formed by the convex portions 11a, 11b provided on one side covering portion 1A of the surface material 10 is the inverse of the unevenness formed by the concave portions 14a, 14b provided on the other side covering portion 1B. Because the unevenness provided on one side covering portion 1A of the sandwich panel 1 is the inverse of the unevenness provided on the other side covering portion 1B, when forming a connecting portion 2 in which the side covering portions 1A, 1B, which are the sides of adjacent sandwich panels 1, are butted together, as shown in FIG. 2(c), the unevenness of the side covering portions 1A, 1B of the adjacent sandwich panels 1 also has the inverse shape of the unevenness, and they can be fitted together. In this embodiment, the side covering portions 1A, 1B of adjacent sandwich panels 1 can be fitted together to form a strong connection, preventing oxygen from flowing into the connecting portion 2, suppressing deterioration of flammability, and improving fire resistance.

[0014] The protrusions 11a and 11b provided on the side surface covering portion 1A and the recesses 14a and 14b provided on the side surface covering portion 1B will be described in detail with reference to FIG. 2(a) and 2(b), the side surface covering portion 1A is provided with protrusions 11a and 11b. The protrusions 11a and 11b are provided on both side surfaces of the side surface covering portion 1A. As shown in Figures 2(a) and 2(b), the side surface covering portion 1B is provided with recesses 14a and 14b. The recesses 14a and 14b are provided on both side surfaces of the side surface covering portion 1B. In this specification, the term "recess" does not only refer to a recess having convex sides, but also to a portion that is simply recessed from the side surface, such as the recesses 14a and 14b shown in Figure 1. The convex portions 11a and 11b provided on the side surface covering portion 1A and the concave portions 14a and 14b provided on the side surface covering portion 1B have inverted shapes. In other words, when two sandwich panels 1 are prepared and the side surface covering portion 1A of one sandwich panel 1 is butted against the side surface covering portion 1B of the other sandwich panel 1 to form the connecting portion 2, the convex portions 11a and 11b provided on the side surface covering portion 1A and the concave portions 14a and 14b provided on the side surface covering portion 1B fit together, respectively, so that the connecting portion 2 between the adjacent sandwich panels 1 can be firmly connected.

[0015] From the viewpoint of improving fire resistance, it is preferable to use a non-combustible surface material for the surface material 10. Examples of non-combustible surface materials include calcium silicate board, gypsum board, FRP, and metal plate, among which metal plate is preferable. The metal plate is not particularly limited, but various steel plates such as galvanized steel plate, Galvalume steel plate (registered trademark), stainless steel plate, and aluminum steel plate can be used.

[0016] The thickness of the surface material 10 is preferably 0.1 to 5 mm, more preferably 0.2 to 3 mm, and even more preferably 0.3 to 1 mm. When the thickness of the surface material 10 is equal to or greater than the above lower limit, high fire resistance can be achieved. Furthermore, when the thickness of the surface material 10 is equal to or less than the above upper limit, the weight of the sandwich panel 1 can be reduced.

[0017] The organic core material 5 is a core material of the sandwich panel 1 made of an organic material such as an organic foam. The organic foam is preferably one selected from the group consisting of urethane foam, phenol foam, styrene foam, PVC foam, and polyolefin foam such as polyethylene foam, and among these, either urethane foam or phenol foam is more preferable, with urethane foam being even more preferable.

[0018] As described above, the organic core material 5 is exposed at the center in the Z-axis direction, and in this exposed portion, one side surface 5A of the core material 5 may have an inverted shape relative to the other side surface 5B of the core material 5. For example, one side surface 5A may have a convex portion, and the other side surface 5B may have a concave portion. This allows the exposed core materials 5, 5 to fit together on the side surfaces 1X, 1Y of adjacent sandwich panels 1. That is, in this embodiment, the side surfaces 1X, 1Y of adjacent sandwich panels 1 are both made up of a core material 5 and a surface material 10 and have unevenness, but the unevenness has an inverted shape relative to each other, and the sandwich panels 1, 1 are fitted together entirely. In addition, in this embodiment, since the core material has an interlocking structure at the center in the X-axis direction as described above, it is also possible to place the core material between two expandable fire-resistant materials 20, as described below.

[0019] Furthermore, in terms of improving fire resistance, it is preferable that the portions of the side surfaces of the sandwich panel 1 that are covered by the side surface covering portions 1A and 1B of the core material 10 have a shape that conforms to the inner surface of the surface material 10 so as to reduce the gap formed between the portions and the inner surface of the surface material 10. Therefore, the portions of the side surfaces 5A and 5B of the organic core material 5 that are covered by the surface material 10 only need to have uneven shapes that correspond to the convex portions 11a and 11b of the side surface covering portion 1A and the concave portions 14a and 14b of the side surface covering portion 1B. However, if the convex portions 11a and 11b and the concave portions 14a and 14b provided on the side surface covering portions 1A and 1B are so fine that it is difficult for the organic core material 5 to conform to them, it is preferable to exclude the fine convex portions 11a and 11b and the concave portions 14a and 14b and form a shape that conforms to the inner surface of the surface material 10.

[0020] The thickness (Z-axis direction) of the organic core material 5 is preferably 10 to 300 mm, more preferably 30 to 150 mm, and even more preferably 50 to 200 mm. When the thickness of the organic core material 5 is within the above range, it has high fire resistance and heat insulation properties and can be made lighter.

[0021] <Urethane foam> The urethane foam used as the organic core material 5 will now be described in more detail. The urethane foam used in this embodiment is formed by curing and foaming a urethane resin composition. The urethane resin contained in the urethane foam is a reaction product obtained by mixing and reacting a polyisocyanate compound and a polyol compound.

[0022] The urethane resin composition that forms the urethane foam generally contains a polyisocyanate compound and a polyol compound. The urethane resin composition preferably further contains a catalyst such as a resinification catalyst or a trimerization catalyst, and a blowing agent, and may also contain additives other than these, such as a foam stabilizer, a flame retardant, an inorganic filler, an antioxidant, a heat stabilizer, a metal damage inhibitor, an antistatic agent, a stabilizer, a crosslinking agent, a lubricant, a softener, a dye, a pigment, and a tackifying resin. The urethane resin composition can also be made flame-retardant, non-flammable, or quasi-non-flammable by incorporating a flame retardant, adjusting the amount of catalyst, or increasing the isocyanate index, as will be described later. In the case of a two-component curing type urethane resin composition, it is preferable to separate it into a polyol liquid agent (first component) containing a polyol compound and an isocyanate liquid agent (second component) containing a polyisocyanate compound. In this case, components other than the polyol compound and the polyisocyanate compound may be appropriately blended into the polyol liquid agent or the isocyanate liquid agent, but are preferably blended into the polyol liquid agent.

[0023] The organic material forming the organic core 5 may consist solely of organic substances, or may contain inorganic substances in addition to organic substances. The organic material contains, for example, an organic substance as the main component, and examples of the organic material include those in which, of the total component amount, organic substances account for, for example, 30 mass % or more, preferably 50 mass % or more, more preferably 70 mass % or more, and even more preferably 80 mass % or more.

[0024] The thermally expandable fire-resistant material 20 is a member that expands due to heating such as a fire. In this embodiment, by disposing the thermally expandable fire-resistant material 20 in the connecting portion 2, the thermally expandable fire-resistant material 20 is heated by a fire or the like and expands, and even if the connecting portion 2 is insufficiently connected, the inflow of oxygen is suppressed to prevent deterioration of combustibility, and by filling gaps that are generated by carbonization and shrinkage of the organic material used as the core material 5, the generation of a heat path can be suppressed, thereby preventing a decrease in fire resistance. As shown in Fig. 1(b), the heat-expandable fire-resistant material 20 is partially disposed in the thickness direction (Z-axis direction) of the sandwich panel 1 at the connecting portion 2. By partially disposing the heat-expandable fire-resistant material 20 in the thickness direction (Z-axis direction) of the sandwich panel 1, it is possible to prevent the material from forming a thermal bridge, thereby improving fire resistance without reducing the thermal insulation performance in the thickness direction.

[0025] The length of the portion where the heat-expandable fire-resistant material 20 is provided in the Z-axis direction of the sandwich panel 1 is not particularly limited, but may be approximately 3 / 4 or less, and preferably approximately 1 / 5 to 2 / 3, of the thickness of the sandwich panel 1. The length of the portion where the heat-expandable fire-resistant material 20 is provided is the length L in the Z-axis direction of the heat-expandable fire-resistant material 20 when only one heat-expandable fire-resistant material 20 is provided in the ZX cross section as shown in a second embodiment (FIG. 4) described later, and is the total length of the lengths L1 and L2 in the Z-axis direction of the heat-expandable fire-resistant materials 20, 20 when two heat-expandable fire-resistant materials are provided in the ZX cross section as in this embodiment. The thermally expandable fire-resistant material 20 is preferably provided over the entire length of the connecting portion 2 in the height direction (Y-axis direction), but may be provided over a portion of the entire length.

[0026] Furthermore, the heat-expandable fire-resistant materials 20 may be partially arranged so that they do not connect in the thickness direction (Z-axis direction) of the sandwich panel 1 even when heated and expanded by a fire or the like. In this embodiment, by partially arranging the heat-expandable fire-resistant materials 20 at the connecting portion 2 so that a part of the core material 5 is present between the two heat-expandable fire-resistant materials 20, it is possible to prevent the heat-expandable fire-resistant materials 20 from forming a thermal bridge in the thickness direction (Z-axis direction) of the sandwich panel 1 even when heated and expanded by a fire or the like, and therefore it is possible to prevent a decrease in fire resistance performance.

[0027] In this embodiment, as shown in FIG. 1( b), the heat-expandable fire-resistant material 20 is preferably disposed in either of the side surface covering portions 1A, 1B of the surface material 10, which are portions that cover the side surfaces 5A, 5B of the core material 5. In order to configure the heat-expandable fire-resistant material 20 to be disposed in the connecting portion 2, the heat-expandable fire-resistant material 20 is adhered to the side surfaces 5A, 5B of the core material 5 or the side surface covering portions 1A, 1B of the surface material 10 by self-adhesion or adhesive tape. Therefore, from the viewpoints of improving adhesion and ease of adhesion, it is preferable that the surface to which the heat-expandable fire-resistant material 20 is adhered is smooth. From these viewpoints, it is preferable to compare the smoothness of the side surfaces 5A, 5B of the core material 5 and the side surface covering portions 1A, 1B of the surface material 10, and to dispose the heat-expandable fire-resistant material 20 on the side surface covering portions 1A, 1B of the surface material 10, which have greater smoothness.

[0028] Furthermore, in the connecting portion 2, the pair of heat-expandable fire-resistant materials 20, 20 are preferably arranged in the Z-axis direction (thickness direction of the panel) on either side of the center in the Z-axis direction, and are preferably arranged symmetrically, more specifically, on either side of the center plane in the thickness direction of the panel. By arranging them on either side of the center, both ends in the Z-axis direction do not become uneven in the event of a fire, and gaps caused by expansion can be prevented, which makes it easier to improve fire resistance.

[0029] The expansion start temperature of the thermally expandable fire-resistant material 20 is not particularly limited, but is preferably 150 to 350°C, more preferably 170 to 300°C, and even more preferably 180 to 280°C. By setting the temperature at or below these lower limit values, the thermally expandable fire-resistant material 20 is prevented from accidentally expanding due to heating other than that caused by a fire. Furthermore, by setting the temperature at or below the upper limit values, the thermally expandable fire-resistant material 20 is more likely to reliably expand due to heating caused by a fire. The expansion start temperature of the heat-expandable fireproof material 20 can be measured by heating a predetermined amount (e.g., 100 mg) of the heat-expandable fireproof material 20 at a constant heating rate (e.g., 10°C / min) and measuring the temperature at which the normal force rises. Any measuring device can be used as long as it is capable of controlling the measurement temperature and measuring the normal stress, and a rheometer, for example, can be used.

[0030] The expansion ratio of the thermally expandable fire-resistant material 20 is preferably 3 times or more, and more preferably 10 times or more. The upper limit of the expansion ratio is not particularly limited, but is, for example, 100 times. The expansion ratio may be calculated by feeding a test piece of the thermally expandable fire-resistant material 20 into an electric furnace, heating it at 600°C for 30 minutes, measuring the thickness of the test piece, and then dividing the thickness of the test piece by the formula: (thickness of the test piece after heating) / (thickness of the test piece before heating).

[0031] The thermally expandable fire-resistant material 20 can be configured to include, for example, a thermally expandable layer formed from a thermally expandable resin composition. In this case, the thermally expandable resin composition contains a resin component and a thermally expandable material. Examples of the thermally expandable material include thermally expandable layered inorganic materials, thermally expandable microcapsules, and intumescent flame retardants. Of these, thermally expandable layered inorganic materials are preferred, and thermally expandable graphite, described below, is particularly preferred. Note that the thermally expandable fire-resistant material 20 does not expand, or if it expands, it is only partial, upon molding, as described below, and the thermal expandability of the thermally expandable resin composition is maintained in the thermally expandable layer.

[0032] <Resin component> Examples of the resin component of the thermally expandable resin composition include thermoplastic resins, thermosetting resins, and elastomers. Examples of thermoplastic resins include polyvinyl chloride (PVC), chlorinated polyvinyl chloride resin (CPVC), fluororesin, polyphenylene ether, modified polyphenylene ether, polyphenylene sulfide, polycarbonate, polyetherimide, polyetheretherketone, polyarylate, polyamide, polyamideimide, polybutadiene, polyimide, acrylic resin, polyacetal, polyamide, polyethylene (PE), polypropylene (PP), polyolefins such as ethylene vinyl acetate (EVA), polyesters such as ethylene-propylene-diene copolymer (EPDM), chloroprene (CR), polyethylene terephthalate, and polybutylene terephthalate, polycarbonate, polystyrene (PS), polyphenylene sulfide, acrylonitrile-butadiene-styrene copolymer (ABS), acrylonitrile-styrene-acrylonitrile copolymer (ASA), and acrylonitrile / ethylene-propylene-diene / styrene copolymer (AES). Examples of the curable resin include epoxy resin, phenol resin, melamine resin, urea resin, unsaturated polyester resin, alkyd resin, polyurethane, and thermosetting polyimide.

[0033] Examples of elastomers include natural rubber, silicone rubber, styrene-butadiene rubber, isoprene rubber, butadiene rubber, chloroprene rubber, acrylonitrile-butadiene rubber, nitrile-butadiene rubber, butyl rubber, ethylene-propylene rubber, ethylene-propylene-diene rubber, urethane rubber, silicone rubber, and fluororubber. Other examples include thermoplastic elastomers such as olefin-based thermoplastic elastomers (TPO), styrene-based thermoplastic elastomers (TPS), ester-based thermoplastic elastomers, amide-based thermoplastic elastomers, and vinyl chloride-based thermoplastic elastomers. The resin component of the thermally expandable resin composition may be one type or a combination of two or more types.

[0034] The thermally expandable resin composition may contain a plasticizer. A plasticizer is preferably used when the resin component is a thermoplastic resin such as polyvinyl chloride resin. Specific examples of the plasticizer include phthalate ester plasticizers such as di-2-ethylhexyl phthalate (DOP), dibutyl phthalate (DBP), diheptyl phthalate (DHP), and diisodecyl phthalate (DIDP); adipic acid esters such as di-2-ethylhexyl adipate (DOA), diisobutyl adipate (DIBA), and dibutyl adipate (DBA), and fatty acid ester plasticizers such as adipic acid polyester; epoxidized ester plasticizers such as epoxidized soybean oil; trimellitic acid ester plasticizers such as tri-2-ethylhexyl trimellitate (TO™) and triisononyl trimellitate (TINT™); phosphate ester plasticizers such as trimethyl phosphate (TMP) and triethyl phosphate (TEP); and process oils such as mineral oil. One or more plasticizers can be used. When the thermally expandable resin composition contains a plasticizer, the content of the plasticizer in the thermally expandable resin composition is, for example, in the range of 0.3 parts by mass to 150 parts by mass, and preferably in the range of 10 parts by mass to 100 parts by mass, relative to 100 parts by mass of the resin component. When the plasticizer content is equal to or greater than these lower limits, good moldability is likely to be achieved, and when it is equal to or less than these upper limits, appropriate strength is imparted to the thermally expandable layer.

[0035] The total content of the resin component and the plasticizer is preferably 10% by mass or more and 90% by mass or less, more preferably 25% by mass or more and 80% by mass or less, and even more preferably 40% by mass or more and 70% by mass or less, based on the total amount of the resin composition. By setting it at or above these lower limits, the moldability of the thermally expandable layer can be improved. On the other hand, by setting it at or below the upper limits, it becomes possible to blend sufficient amounts of components such as thermally expandable graphite and inorganic filler. The total content of the resin component and the plasticizer means the total content of both the resin component and the plasticizer when both are contained, and means the content of the resin component alone when no plasticizer is contained.

[0036] <Thermal Expandable Layered Inorganic Material> The thermally expandable layered inorganic material is a conventionally known substance that expands when heated, such as vermiculite or thermally expandable graphite, among which thermally expandable graphite is preferred. As the thermally expandable layered inorganic material, particulate or flake-shaped materials can be used. Thermally expandable graphite expands appropriately when heated by fire, and the expanded residue after expansion has excellent mechanical strength, which makes it easier to improve fire resistance. Thermally expandable graphite is a conventionally known substance, and is produced by treating powder of natural flake graphite, pyrolytic graphite, kish graphite, or the like with an inorganic acid such as concentrated sulfuric acid, nitric acid, or selenic acid, and a strong oxidizing agent such as concentrated nitric acid, perchloric acid, perchlorates, permanganates, dichromates, or hydrogen peroxide to produce a graphite intercalation compound. The produced thermally expandable graphite is a crystalline compound that maintains the layered structure of carbon. Thermally expandable graphite that has been acid-treated and then neutralized with ammonia, aliphatic lower amines, alkali metal compounds, alkaline earth metal compounds, or the like can also be used. Examples of the aliphatic lower amine include monomethylamine, dimethylamine, trimethylamine, ethylamine, propylamine, and butylamine. Examples of the alkali metal compounds and alkaline earth metal compounds include hydroxides, oxides, carbonates, sulfates, and organic acid salts of potassium, sodium, calcium, barium, magnesium, and the like. The particle size of the thermally expandable graphite is not particularly limited, but is preferably in the range of 20 to 200 mesh. If the particle size is equal to or greater than the lower limit, the degree of expansion of the graphite tends to increase, resulting in good expandability. On the other hand, if the particle size is equal to or less than the upper limit, good dispersibility when kneaded with a resin is achieved, improving moldability.

[0037] The content of thermally expandable graphite in the thermally expandable resin composition is, for example, 1 part by mass or more and 200 parts by mass or less, relative to 100 parts by mass of the resin component. When the content of thermally expandable graphite is 1 part by mass or more, thermal expandability is improved. When the content is 200 parts by mass or less, moldability, mechanical properties, and the like are also improved. From these viewpoints, the content of thermally expandable graphite is preferably in the range of 10 parts by mass or more and 150 parts by mass or less, and more preferably in the range of 15 parts by mass or more and 100 parts by mass or less.

[0038] <Thermal expansion microcapsules> Thermally expandable microcapsules have a volatile substance such as a low-boiling point solvent encapsulated inside a resin shell. When heated, the resin shell softens, causing the encapsulated volatile substance to volatilize or expand, resulting in pressure that causes the shell to expand and increase in particle size. Thermally expandable microcapsules exhibit an insulating effect due to the bubbles formed after expansion, which can be expected to improve insulating performance.

[0039] The outer shell of the thermally expandable microcapsules is preferably formed from a thermoplastic resin. The thermoplastic resin can be one or more selected from vinyl polymers such as ethylene, styrene, vinyl acetate, vinyl chloride, vinylidene chloride, acrylonitrile, butadiene, and chloroprene, copolymers thereof, polyamides such as nylon 6 and nylon 66, and polyesters such as polyethylene terephthalate. Among these, acrylonitrile copolymers are preferred because they are less permeable to encapsulated volatile substances. Examples of volatile substances encapsulated in the thermally expandable microcapsules include one or more low-boiling liquids selected from hydrocarbons having 3 to 7 carbon atoms such as propane, propylene, butene, normal butane, isobutane, isopentane, neopentane, normal pentane, hexane, and heptane; methane halides such as methyl chloride and methylene chloride; chlorofluorocarbons such as CCl3F and CCl2F2; tetraalkylsilanes such as tetramethylsilane and trimethylethylsilane; and petroleum ether. A suitable example of the thermally expandable microcapsule is a microcapsule having a shell resin of a copolymer of acrylonitrile and vinylidene chloride, and encapsulating a hydrocarbon having 3 to 7 carbon atoms, such as isobutane. When using thermally expandable microcapsules, it is particularly preferable to use them in combination with at least one selected from the thermally expandable solid phosphorus compounds described above and the solid flame retardants described below. By using them in combination, the thermally expandable microcapsules can be maintained in an expanded state even at high temperatures and achieve a high expansion ratio when heated to 600°C.

[0040] The content of the thermally expandable microcapsules in the thermally expandable resin composition is, for example, 1 part by mass or more and 200 parts by mass or less, relative to 100 parts by mass of the resin component. When the content of the thermally expandable microcapsules is 1 part by mass or more, the thermal expandability is good. When the content is 200 parts by mass or less, the moldability, mechanical properties, and the like are also good. From these viewpoints, the content of the thermally expandable microcapsules is preferably in the range of 10 parts by mass or more and 150 parts by mass or less, and more preferably in the range of 15 parts by mass or more and 100 parts by mass or less.

[0041] <Intumescent flame retardant> Examples of intumescent flame retardants include those that use, as reactive compounds, polyphosphates of polyalkylene polyamines such as ammonium polyphosphate and melamine polyphosphate; as foam skeleton-forming agents, hydrocarbon compounds such as dextrin, polyfunctional alcohols such as pentaerythritol, and hydrocarbon compounds such as polyvinyl acetate; as blowing agents, decomposable ammonium salts, amide compounds such as dicyanamide and melamine; and as vehicles, for example, aqueous synthetic emulsions, solvent-based alkyd resins, epoxy resins, and the like.

[0042] The content of the intumescent flame retardant in the thermally expandable resin composition is, for example, 1 part by mass or more and 200 parts by mass or less, relative to 100 parts by mass of the resin component. When the content of the intumescent flame retardant is 1 part by mass or more, the thermal expandability is good. When the content is 200 parts by mass or less, the moldability, mechanical properties, and the like are also good. From these viewpoints, the content of the intumescent flame retardant is preferably in the range of 10 parts by mass or more and 150 parts by mass or less, and more preferably in the range of 15 parts by mass or more and 100 parts by mass or less.

[0043] 《Inorganic filler》 The thermally expandable resin composition may further contain an inorganic filler other than the thermally expandable material. The inorganic filler is not particularly limited as long as it is an inorganic filler that is generally used in thermally expandable resin compositions. Specific examples include silica, diatomaceous earth, alumina, zinc oxide, titanium oxide, calcium oxide, magnesium oxide, iron oxide, tin oxide, antimony oxide, ferrites, calcium hydroxide, magnesium hydroxide, aluminum hydroxide, basic magnesium carbonate, calcium carbonate, magnesium carbonate, zinc carbonate, barium carbonate, dawnnite, hydrotalcite, calcium sulfate, barium sulfate, gypsum fiber, calcium silicate, talc, clay, mycelium, montmorillonite, bentonite, activated clay, seviolite, imogolite, sericite, glass fiber, glass beads, silica balloon, aluminum nitride, aluminum phosphite, boron nitride, silicon nitride, carbon black, graphite, carbon fiber, carbon balloon, charcoal powder, various metal powders, potassium titanate, magnesium sulfate, lead zirconium titanate, aluminum borate, molybdenum sulfide, silicon carbide, stainless steel fiber, zinc borate, various magnetic powders, slag fiber, fly ash, and dewatered sludge. The inorganic filler may be used alone or in combination of two or more. When an inorganic filler is contained, the content of the inorganic filler in the thermally expandable resin composition is preferably in the range of 3 parts by mass or more and 200 parts by mass or less, and more preferably in the range of 10 parts by mass or more and 150 parts by mass or less, per 100 parts by mass of the resin component.

[0044] <<Tackifier>> The thermally expandable resin composition may contain a known tackifier. By containing a tackifier, it becomes easier to impart tackiness to the thermally expandable layer itself, and it is also possible to impart self-adhesiveness. Furthermore, the thermally expandable resin composition used in the present invention may contain, as needed, additives commonly used in thermally expandable resin compositions, such as flame retardants, heat-absorbing agents, heat stabilizers, lubricants, processing aids, antioxidants, antistatic agents, pigments, crosslinking agents, crosslinking accelerators, etc. Among these, it is preferable to use processing aids.

[0045] The thermally expandable fire-resistant material 20 may be composed of a single thermally expandable layer, or may be a laminate having a thermally expandable layer and a substrate. The laminate may have a two-layer structure of a thermally expandable layer and a substrate, or an adhesive layer may be provided between the thermally expandable layer and the substrate. Alternatively, the laminate may be a laminate having two or more layers of at least one of a thermally expandable layer and a substrate. The substrate is preferably made of a non-combustible material, and examples of the non-combustible material include metal sheets such as aluminum foil, glass cloth, and composites of metal sheets and glass cloth such as aluminum glass cloth, with aluminum glass cloth being particularly preferred. Moreover, commercially available products such as "Fi-Block" manufactured by Sekisui Chemical Co., Ltd. can also be used as the thermally expandable fireproof material.

[0046] The heat-expandable fire-resistant material 20 may also be in a putty form. The shape of the putty-like heat-expandable fire-resistant material 20 can be adjusted appropriately during construction, and it can be attached to the sandwich panel 1 in the desired shape. The putty-like heat-expandable fire-resistant material 20 may be made of the heat-expandable resin composition described above. In this case, the heat-expandable fire-resistant material 20 can be made into a putty form by appropriately selecting the resin component. The putty-like heat-expandable fire-resistant material 20 may also be made of clay containing a heat-expandable material. The putty-like heat-expandable fire-resistant material 20 may be a hardening type or a non-hardening type. Examples of the putty-like heat-expandable fire-resistant material 20 include the "Plaseal" series manufactured by Nitto Kasei Kogyo Co., Ltd.

[0047] A manufacturing method according to one embodiment of the sandwich panel connection structure 100 according to this embodiment includes a step of preparing sandwich panels 1 and a step of connecting the sandwich panels 1 together. In the process of preparing the sandwich panel 1, first, a urethane resin composition is foamed and cured to form a urethane foam. In this case, the urethane foam may be formed by injecting the urethane resin composition into a form or the like, foaming and curing it inside the form or the like, and then releasing it from the form to form the organic core material 5 having the desired shape, or the urethane foam may be processed into the desired shape by cutting or the like to form the organic core material 5. Next, a non-combustible surface material is prepared and bent to form surface material 10 having main surface covering portions 1C, 1D and side surface covering portions 1A, 1B. Surface material 10 may consist of a single sheet of non-combustible surface material, or may consist of multiple sheets of non-combustible surface material. Next, the sandwich panel 1 can be manufactured by arranging the main surface covering portions 1C, 1D and side surface covering portions 1A, 1B of the surface material 10 so that they cover part of the main surfaces 5C, 5D and side surfaces 5A, 5B of the organic core material 5.

[0048] The sandwich panel of the present invention can also be manufactured by filling a urethane resin composition between the surface materials, foaming and curing the urethane resin composition to form a urethane foam, and integrating the urethane foam with the surface materials. Although the above description has been given using an example of a form for producing urethane foam, foams other than urethane foam can also be produced in the same manner by using a resin composition for forming a foam instead of the urethane resin composition.

[0049] Next, heat-expandable fire-resistant materials 20 are prepared, and as shown in Figures 2(a) and (b), two heat-expandable fire-resistant materials 20 are bonded and fixed so that they are spaced apart and partially arranged on the side covering portion 1A of the surface material 10. Then, as shown in Figures 2(a) and (b), the prepared multiple sandwich panels 1 are arranged adjacent to each other and connected by connecting portions 2 where the side surfaces 1X, 1Y of a pair of adjacent sandwich panels 1 are butted together, thereby obtaining a sandwich panel connection structure 100.

[0050] According to the sandwich panel connection structure 100 of this embodiment described above, when a connection portion 2 is formed by butting together the side covering portions 1A, 1B, which are the side surfaces of adjacent sandwich panels 1, a heat-expandable fire-resistant material 20 is placed in the connection portion 2, so that the heat-expandable fire-resistant material 20 is heated and expanded by a fire or the like, and even if the connection at the connection portion 2 is insufficient, the inflow of oxygen can be suppressed to prevent a deterioration in flammability, and by filling gaps created by the carbonization and shrinkage of the organic material used as the core material 5, the generation of heat paths can be suppressed and a decrease in fire resistance can be prevented. Furthermore, according to the sandwich panel connection structure 100 of this embodiment, the connection portion 2 is partially arranged in the thickness direction (Z-axis direction) of the sandwich panel 1, which makes it possible to prevent a thermal bridge from forming in the thickness direction (Z-axis direction) of the sandwich panel 1, thereby preventing a decrease in insulation properties. Furthermore, according to the sandwich panel connection structure 100 of this embodiment, when forming the connection portion 2 by butting together the side covering portions 1A and 1B, which are the side surfaces of adjacently arranged sandwich panels 1, the connection portion 2 is formed by fitting together the convex portions and concave portions provided on the side covering portions 1A and 1B, respectively, thereby preventing oxygen from flowing into the connection portion 2 and suppressing a deterioration in flammability.

[0051] [Modification of the first embodiment] In the first embodiment, to obtain the sandwich panel connection structure 100 shown in Figure 2(c), as shown in Figures 2(a) and (b), two heat-expandable fire-resistant materials 20 are arranged in the side covering portion 1A of the surface material 10 of one adjacent sandwich panel 1, and when the other adjacent sandwich panel 1 is connected, the two heat-expandable fire-resistant materials 20 are spaced apart and partially arranged at the connection portion 2. However, to obtain the sandwich panel connection structure 1 shown in Figure 2(c), this is not limited to this, and the heat-expandable fire-resistant materials 20 may be arranged in a configuration as shown in Figures 3(a) and (b), where one heat-expandable fire-resistant material 20 is arranged on each of the side surfaces 1X and 1Y of a pair of adjacent sandwich panels 1, and when the adjacent sandwich panels 1 are connected, the two heat-expandable fire-resistant materials 20 are spaced apart and partially arranged at the connection portion 2.

[0052] 3(a) and (b), the heat-expandable fire-resistant material 20 in the modified example of the first embodiment is arranged at the end of the side surface 1X of one adjacent sandwich panel 1 on the side of the main surface covering portion 1C, and at the end of the side surface 1B of the other adjacent sandwich panel 1 on the side of the main surface covering portion 1D. When a pair of adjacent sandwich panels 1 are connected, as shown in FIG. 3(c), a configuration substantially similar to the connection structure of the sandwich panels 1 shown in FIG. 2(c) can be obtained.

[0053] [Second embodiment] Next, a second embodiment of the present invention will be described in detail. The second embodiment differs from the first embodiment in that, as shown in FIG. 4, the thermally expandable fire-resistant material 20 is arranged on the side surfaces 5A and 5B of the core material 5. The differences between the first embodiment and the second embodiment will be described below. Furthermore, parts whose description is omitted are the same as those in the first embodiment. Furthermore, in the following description, parts having the same configuration as those in the first embodiment will be given the same reference numerals.

[0054] As shown in FIGS. 4(a) and 4(b), the heat-expandable fire-resistant material 20 is disposed on the side surface 5A of the core material 5. In the first embodiment, when the heat-expandable fire-resistant material 20 is disposed by being adhered with self-adhesive force or adhesive tape, etc., the smoothness of the side surfaces 5A, 5B of the core material 5 is compared with that of the side surface covering portions 1A, 1B of the surface material 10, and the heat-expandable fire-resistant material 20 is disposed on the side surface covering portions 1A, 1B of the surface material 10, which have higher smoothness, from the viewpoint of improving the adhesion of the heat-expandable fire-resistant material 20 and facilitating adhesion. In the present embodiment, the heat-expandable fire-resistant material 20 may be disposed on the side surface 5A of the core material 5 when the smoothness of the side surfaces 5A, 5B of the core material 5 is equivalent to that of the side surface covering portions 1A, 1B of the surface material 10, or when the smoothness of the side surfaces 5A, 5B of the core material 5 is high. Furthermore, when the heat-expandable fire-resistant material 20 is in a putty form, from the viewpoint of ease of installation of the putty-like heat-expandable fire-resistant material 20, it is preferable to compare the smoothness of the side surfaces 5A, 5B of the core material 5 with that of the side covering portions 1A, 1B of the surface material 10, and to place the heat-expandable fire-resistant material 20 on the side surfaces 5A, 5B of the core material 5 which are less smooth and have a larger installation surface area. In an embodiment in which the heat-expandable fire-resistant material 20 is placed on the side surface 5A of the core material 5, the sides 1X and 1Y of a pair of adjacent sandwich panels 1 are connected by a connecting portion 2 that butts together, so that the heat-expandable fire-resistant material 20 is positioned so as to be sandwiched between the sides 5A and 5B of the core material 5, as shown in Figure 4(c). The heat-expandable fire-resistant material 20 is provided at the center in the thickness direction (Z-axis direction) of the sandwich panel 1 at the connecting portion 2. By providing the heat-expandable fire-resistant material 20 at the center in the thickness direction (Z-axis direction) of the sandwich panel 1, even if the heat-expandable fire-resistant material 20 expands in the event of a fire, both ends in the Z-axis direction will not become uneven, thereby preventing a decrease in fire resistance performance.

[0055] According to the sandwich panel connection structure 100 according to the second embodiment of the present invention, it is possible to obtain the same effects as those of the sandwich panel connection structure 100 according to the first embodiment. In addition, in the second embodiment, the heat-expandable fire-resistant material 20 is arranged so as to be sandwiched between the side surfaces 5A and 5B of the core material 5, which makes it easier to fill gaps that occur due to carbonization and shrinkage of the organic material used as the core material 5 in the event of a fire, etc., thereby suppressing the occurrence of heat paths and preventing a decrease in fire resistance performance.

[0056] [Third embodiment] Next, a third embodiment of the present invention will be described in detail. The third embodiment differs from the first embodiment in that, as shown in FIG. 5, gaps 50 and 51 are provided on the side surfaces 1X and 1Y of the sandwich panel 1, and partition members 6 are arranged in the gaps 50 and 51. The third embodiment also differs from the first embodiment in that the surface material 10 has convex portions 11a and 11b and concave portions 12a and 12b on the side surface covering portion 1A, and convex portions 13a and 13b and concave portions 14a and 14b on the side surface covering portion 1B. Differences between the first embodiment and the third embodiment will be described below. Portions whose description is omitted are similar to those of the first embodiment. In the following description, components having the same configuration as those of the first embodiment will be designated by the same reference numerals.

[0057] 5(a) and 5(b), the sandwich panel 1 according to this embodiment is configured so that when adjacent sandwich panels 1 are butted side by side, a partition material 6 is further provided at the connecting portion 2. In order to do this, a gap 51 having a shape that allows the partition material 6 to be inserted into the side surface 5A and a depth that allows the partition material 6 to be inserted is provided. In addition, a gap 50 having a shape that allows the partition material 6 to be inserted into the side surface 5B of the organic core material 5 and a depth that allows the partition material 6 to be inserted is provided. As shown in Figure 5(c), the gaps 50, 51 are provided at the positions of the sides 5A, 5B of the opposing organic core material 5 when the sandwich panels 1 are adjacent and the sides are butted together, and when the connecting portion 2 is formed, the partition material 6 is inserted into the space created by the gaps 50, 51.

[0058] The partition material 6 is inserted between both side surfaces 1X and 1Y of the sandwich panel 1, thereby more firmly connecting the adjacent sandwich panels 1, 1. The partition material 6 also functions as a thermal separator for heat conduction in the thickness direction (Z-axis direction) of the sandwich panel 1 (heat conduction from the principal surface covering portion 1C to the principal surface covering portion 1D, or heat conduction from the principal surface covering portion 1D to the principal surface covering portion 1C). Therefore, for example, the thermally expandable fire-resistant materials 20 are prevented from expanding and coming into contact with each other after expansion, and the formation of a thermal bridge by the expanded heat-expandable fire-resistant materials 20 can be prevented. The partition material 6 is a plate-like member, and its material is not particularly limited, and examples thereof include inorganic materials such as calcium silicate board, concrete, and gypsum board.

[0059] The gaps 50, 51 and the partition material 6 may be provided over the entire height (Y-axis direction) of the side covering portions 1A, 1B, or may be provided over part of the entire height (Y-axis direction) of the side covering portions 1A, 1B.

[0060] The width (Z-axis direction) of the partition material 6 is preferably 1 to 30 mm, more preferably 2 to 25 mm, and even more preferably 3 to 20 mm. When the width of the partition material 6 is within the above range, the heat insulation between the compartments can be improved. Furthermore, the length (X-axis direction) of the partition material 6 is preferably 20 to 100 mm, more preferably 30 to 85 mm, and even more preferably 50 to 70 mm. By keeping the length of the partition material 6 within the above range, the thermal insulation between the compartments can be improved.

[0061] The protrusions 11a, 11b, 13a, and 13b and the recesses 12a, 12b, 14a, and 14b provided on the side surface covering portions 1A and 1B will be described in detail with reference to FIG. 5(a) and 5(b), the side surface covering portion 1A is provided with protrusions 11a and 11b and recesses 12a and 12b. The recesses 12a and 12b are provided on both side surfaces of the side surface covering portion 1A. The widths (Z-axis direction) of the protrusions 11a and 11b and the recesses 12a and 12b are approximately the same, but the length (X-axis direction) of the recesses 12a and 12b is greater. 5(a) and 5(b), the side surface covering portion 1B is provided with protrusions 13a and 13b and recesses 14a and 14b. The protrusions 13a and 13b are provided on both side surfaces of the side surface covering portion 1B. The widths (in the Z-axis direction) of the protrusions 13a and 13b and the recesses 14a and 14b are approximately the same, but the length (in the X-axis direction) of the protrusions 13a and 13b is greater. The convex portions 11a and 11b provided on the side covering portion 1A and the concave portions 14a and 14b provided on the side covering portion 1B have inverted shapes. Furthermore, the concave portions 12a and 12b provided on the side covering portion 1A and the convex portions 13a and 13b provided on the side covering portion 1B have inverted shapes. That is, when two sandwich panels 1 are prepared and the side covering portion 1A of one sandwich panel 1 is butted against the side covering portion 1B of the other sandwich panel 1 to form a connecting portion 2, the convex portions 11a and 11b provided on the side covering portion 1A and the concave portions 14a and 14b provided on the side covering portion 1B fit together, respectively, and the concave portions 12a and 12b provided on the side covering portion 1A and the convex portions 13a and 13b provided on the side covering portion 1B fit together, thereby enabling a stronger connection between the connecting portion 2 of adjacent sandwich panels 1.

[0062] According to the sandwich panel 1 and sandwich panel connection structure 100 according to the third embodiment of the present invention, it is possible to obtain the same effects as those of the sandwich panel connection structure 100 according to the first embodiment. In addition, in the third embodiment, a partition material 6 is further provided at the connecting portion 2 where the side surfaces of the sandwich panel 1 are butted together, so that when the connecting portion 2 is configured, the partition material 6 can function as a thermal edge separator for heat conduction in the thickness direction of the sandwich panel 1.

[0063] [Modification of the third embodiment] In the third embodiment, to obtain the sandwich panel connection structure 100 shown in Figure 5(c), as shown in Figures 5(a) and (b), two heat-expandable fire-resistant materials 20 are arranged in the side covering portion 1A of the surface material 10 of one adjacent sandwich panel 1, and when the other adjacent sandwich panel 1 is connected, the two heat-expandable fire-resistant materials 20 are spaced apart and partially arranged at the connection portion 2. However, to obtain the sandwich panel connection structure 1 shown in Figure 5(c), this is not limited to this, and the heat-expandable fire-resistant materials 20 may be arranged in a configuration as shown in Figures 6(a) and (b), where one heat-expandable fire-resistant material 20 is arranged on each of the side surfaces 1X and 1Y of a pair of adjacent sandwich panels 1, and when the adjacent sandwich panels 1 are connected, the two heat-expandable fire-resistant materials 20 are spaced apart and partially arranged at the connection portion 2.

[0064] As shown in Figures 6(a) and (b), in the modified example of the third embodiment, the heat-expandable fire-resistant material 20 is arranged at the end of the side surface 1X of one adjacent sandwich panel 1 on the side of the main surface covering portion 1C, and at the end of the side surface 1B of the other adjacent sandwich panel 1 on the side of the main surface covering portion 1D. Then, when a pair of adjacent sandwich panels 1 are connected, as shown in Figure 6(c), a configuration substantially similar to the connection structure of the sandwich panels 1 shown in Figure 5(c) can be obtained.

[0065] [Fourth embodiment] Next, a fourth embodiment of the present invention will be described in detail. The fourth embodiment differs from the third embodiment in that, as shown in FIG. 7, the heat-expandable fire-resistant material 20 in the third embodiment is replaced with a plate-shaped heat-expandable fire-resistant material 7, and the plate-shaped heat-expandable fire-resistant material 7 is disposed in place of the partition material 6. Hereinafter, the differences between the fourth embodiment and the third embodiment will be described. Furthermore, parts whose description is omitted are the same as those in the third embodiment. Furthermore, in the following description, members having the same configuration as those in the first embodiment will be assigned the same reference numerals.

[0066] The thermally expandable fire-resistant material 7 can be configured in a plate shape having a thermally expandable layer formed from the above-mentioned thermally expandable resin composition.

[0067] The voids 50, 51 and the thermally expandable fire-resistant material 7 may be provided over the entire height (Y-axis direction) of the side covering portions 1A, 1B, or may be provided over part of the entire height (Y-axis direction) of the side covering portions 1A, 1B.

[0068] The width (Z-axis direction) of the thermally expandable fire-resistant material 7 is preferably 1 to 30 mm, more preferably 2 to 25 mm, and even more preferably 3 to 20 mm. When the width of the thermally expandable fire-resistant material 7 is within the above range, it expands well when heated by a fire or the like, and the fire resistance between the compartments can be improved. The length (X-axis direction) of the thermally expandable fire-resistant material 7 is preferably 20 to 100 mm, more preferably 30 to 85 mm, and even more preferably 50 to 70 mm. When the length of the thermally expandable fire-resistant material 7 is within the above range, it expands well when heated by a fire or the like, and the fire resistance between the compartments can be improved.

[0069] According to the sandwich panel connection structure 100 relating to the fourth embodiment of the present invention, it is possible to obtain the same effects as those of the sandwich panel connection structure 100 relating to the first embodiment. In addition, in the fourth embodiment, the heat-expandable fire-resistant material 7 is arranged so as to be sandwiched between the side surfaces 5A and 5B of the core material 5, so that it expands well when heated by a fire or the like, making it easier to fill gaps that arise due to the carbonization and shrinkage of the organic material used as the core material 5, thereby suppressing the occurrence of heat paths and preventing a decrease in fire resistance performance.

[0070] [Modification of the fourth embodiment] In the fourth embodiment, the sandwich panel connection structure 100 has a configuration in which the plate-shaped heat-expandable fire-resistant material 7 is a member that expands when heated by a fire or the like, as shown in Fig. 7. However, the heat-expandable fire-resistant material 7 is not limited to a plate-shaped configuration having a heat-expandable layer formed from the above-mentioned heat-expandable resin composition, and may also have a configuration in which the above-mentioned heat-expandable resin composition is provided on the surface of the partition material 6, as shown in Fig. 8.

[0071] The connection portion 2 of the sandwich panel connection structure 100 according to the modified example of the fourth embodiment is configured to further include a thermally expandable fire-resistant material 7A on the surface of the partition material 6 serving as a thermal edge separation portion. Examples of means for providing the surface of the partition material 6 with heat-expandable fire-resistant material 7A include a means for attaching a sheet-like heat-expandable fire-resistant material 7A to the surface of the partition material 6, and a means for applying liquid heat-expandable fire-resistant material 7A to the surface of the partition material 6 and allowing it to solidify.

[0072] [Other embodiments] The present invention is not limited to the configurations of the above-described first to fourth embodiments, and any improvements and modifications may be made without departing from the technical spirit of the present invention. For example, the convex portions provided on the side surface covering portion 1A in the first to fourth embodiments may be changed to concave portions, and the concave portions provided on the side surface covering portion 1B may be changed to convex portions. Furthermore, in the first to fourth embodiments, the convex and concave portions of the side covering portion 1A of the sandwich panel 1 have the inverted shape of the concave and convex portions of the side covering portion 1B, but as long as the concave and convex portions of the side covering portions of adjacent sandwich panels 1 that are butted together when forming the sandwich panel connection structure 100 have the inverted shape, the two side covering portions of the same sandwich panel 1 do not have to have the inverted shape.

[0073] In the above description, the core material of the sandwich panel 1 is an organic core material. However, a portion of the core material may be an inorganic core material. Specifically, as shown in FIG. 9(a), in the sandwich panel connection structure 100 shown in the first embodiment, the core material on the side surfaces 5A and 5B may be an inorganic core material 8, and the core material between them may be an organic core material 5. Also, as shown in FIG. 9(b), in the sandwich panel connection structure 100 shown in the third embodiment, the core material on the side surfaces 5A and 5B may be an inorganic core material 8, and the core material between them may be an organic core material 5. By using the inorganic core material 8 as the core material on the side surfaces 5A and 5B of the surface material 10, the mechanical strength of the side surface covering portions 1A and 1B of the surface material 10 can be improved. Therefore, when forming the connecting portion 2 where the side surface covering portions 1A and 1B are butted together, the shape of the side surface covering portions 1A and 1B can be maintained, thereby enabling the connecting portion 2 to be stably formed. As the inorganic core material 8, rock wool, ceramic wool, gypsum, calcium silicate, glass wool, etc. can be used. In this embodiment, the organic core material may occupy, for example, 50% by volume or more of the core material 5, preferably 65% ​​by volume or more, and more preferably 80% by volume or more.

[0074] The core material 5 may be divided into multiple pieces, for example, it may be divided into multiple pieces in the X-axis direction. In this case, for example, the sandwich panel 1 can be obtained by inserting multiple core materials 5 into a surface material 10 that has been processed into a square frame shape in advance. Alternatively, the sandwich panel 1 can be obtained by inserting multiple core materials 5 between two U-shaped surface materials 10. Furthermore, by dividing the core material 5, depending on the application and mode of use, the entire core material 5 can be made of organic core material, or part of the core material 5 can be made of inorganic core material and the rest can be made of organic core material, as shown in Figure 9.

[0075] In the above explanation, a configuration has been shown in which adjacent sandwich panels 1 are connected by fitting a convex portion and a concave portion when the side surfaces 1X, 1Y of the sandwich panels 1 are butted together, but as shown in Figures 10(a) and 10(b), a configuration in which a filler 9 is placed in a fitting portion 90 may also be used. In other words, the concave portion and convex portion of one sandwich panel 1 may be structured to fit into the convex portion and concave portion of the other sandwich panel 1 via a filler 7. 10(a) and (b) show a configuration in which the filler 9 is placed over the entire fitting portion 90 that constitutes the connecting portion 2, but a configuration in which the filler 9 is placed over only a portion of the fitting portion 90 that constitutes the connecting portion 2 may also be used. For example, as shown in FIG. 10(b), a configuration in which the filler 9 is placed in the fitting portion 90 in the center of the connecting portion 2 and the filler 9 is not placed in the small recesses and protrusions at both ends may also be used. By configuring the fitting portion 90 to have filler material 9 placed therein, even if gaps occur due to precision errors in the convex and concave portions provided in the side covering portions 1A and 1B, the gaps can be filled with filler material 9, thereby enabling the connection between adjacent sandwich panels 1 to be firmly constructed. In addition, as shown in Figures 10(a) and (b), when a filler 9 is placed in the fitting portion 90, the area where the filler 9 is placed also functions as a thermal isolation portion for heat conduction in the X-axis direction of the sandwich panel 1. As the filler 9, a material having fire resistance and heat insulation properties, such as rock wool, ceramic wool, or glass wool, and having the ability to conform to the fitting portion 90 can be used.

[0076] The side surfaces of the sandwich panel 1 are not limited to the configurations of the above-described embodiments as long as the concave and convex shapes fit together, and may be in other forms, such as the structure shown in Fig. 11. In this form, the surface material 10 may have a pair of convex portions 11a, 11b at both ends in the Z-axis direction of the side surface of one sandwich panel 11, and a pair of concave portions 14a, 14b at both ends in the Z-axis direction of the side surface of the other sandwich panel 11, with concave and convex portions made of the core material and the surface material provided in the center in the Z-axis direction between them.

[0077] Furthermore, in the sandwich panel 1 in the above embodiment, both side surfaces 1X and 1Y of the same panel are provided with irregularities and have mutually inverted shapes, but as long as the irregularities on the butted side surfaces 1X and 1Y of adjacent sandwich panels 1 have mutually inverted shapes when forming a sandwich panel connection structure, both side surfaces of the same sandwich panel 1 do not have to have inverted shapes. Therefore, the shape of the side surface of the sandwich panel 1 that does not form the connection portion is not particularly limited and does not have to have irregularities. In addition, although the side surfaces 5A, 5B of the core material 5 of the sandwich panel 1 are shown as being partially covered by the surface material, the side surfaces 5A, 5B of the core material 5 may be entirely covered by the surface material or may not be covered by the surface material. Furthermore, in each of the above embodiments, on the sides 1A and 1B of the panel 1, in addition to the surface material 10, the core materials 5 also have an inverted shape, and if there are convex or concave portions, these are fitted together, but the core materials 5 do not have to be fitted together, and they do not have to have an inverted shape. Furthermore, the side surfaces 1X, 1Y of the adjacent sandwich panels 1 that form the connecting portion 2 do not need to be fitted together as long as they can be connected to each other, and therefore, no unevenness needs to be provided. [Explanation of symbols]

[0078] 1. Sandwich panel 10 Surface material 20 Thermally expandable fireproofing material 1A, 1B Side covering part 1C,1D Main surface coating part 11 Convex part 12 recess 13 Convex part 14 Recess 2 Connecting part 3 Upper frame material 3A Ceiling 4 Lower frame material 4A floor 5 Core material 5A,5B side 5C,5D main surface 6 Partition material 7,7A thermally expandable fireproofing material 8. Inorganic core material 9 Filling material 50,51 void 90 Fitting part

Claims

1. A sandwich panel connection structure in which sandwich panels having at least two main surfaces opposing each other in a thickness direction and two side surfaces connecting the two opposing main surfaces, and including a core material containing an organic core material and a surface material covering at least the main surfaces of the core material, are arranged adjacent to each other, A sandwich panel connection structure in which a pair of adjacent sandwich panels are connected by a connecting portion where the sides of the sandwich panels are butted together, and a heat-expandable fire-resistant material is partially arranged in the thickness direction of the sandwich panels at the connecting portion.

2. 2. The sandwich panel connection structure according to claim 1, wherein the heat-expandable fire-resistant material is arranged on at least one of the portion of the surface material covering the side surface of the core material and the side surface of the core material.

3. The sandwich panel connection structure according to claim 1 or 2, wherein the organic core material is an organic foam.

4. 3. A sandwich panel connection structure as described in claim 1 or 2, wherein at least one pair of the heat-expandable fire-resistant materials is provided, and the pair of heat-expandable fire-resistant materials are arranged on either side of the central portion in the thickness direction of the sandwich panel.

5. 3. The sandwich panel connection structure according to claim 1, wherein the heat-expandable fire-resistant material is provided at a central portion in the thickness direction of the sandwich panel.

6. The sandwich panel connection structure according to claim 1 or 2, wherein the side surfaces of the sandwich panels constituting the connection portion are all provided with projections and recesses and are fitted together.

7. The sandwich panel connection structure according to claim 1 or 2, further comprising a partition material at the connection portion.

8. The sandwich panel connection structure according to claim 1 or 2, further comprising a filler material in the connection portion.

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